Найти количество слов с заданными символами

REM string_2
CLS
DIM latter$
DIM c1$
DIM c2$
DIM c3$
check1 = false
check2 = false
check3 = false
PRINT "Vvedit re4ennja:"
INPUT latter$
INPUT "Vvedit 1-i sumvol: ", c1$
INPUT "Vvedit 2-i sumvol: ", c2$
INPUT "Vvedit 3-i sumvol: ", c3$
FOR i = 1 TO LEN(latter$)
    IF latter$(i) = " " THEN
        IF check1 AND check2 AND check3 THEN k = k + 1
        check1 = false
        check2 = false
        check3 = false
    ELSEIF latter$(i) = c1$ THEN
        check1 = true
    ELSEIF latter$(i) = c2$ THEN
        check2 = true
    ELSEIF latter$(i) = c3$ THEN
        check3 = true
    END IF
NEXT
PRINT
PRINT "Kilkist sliv v re4enni sho mistjat zadani sumvolu: "; k
END

REM string_2
CLS
DIM latter$
DIM c1$
DIM c2$
DIM c3$
check1 = false
check2 = false
check3 = false
PRINT "Vvedit re4ennja:"
INPUT latter$
INPUT "Vvedit 1-i sumvol: ", c1$
INPUT "Vvedit 2-i sumvol: ", c2$
INPUT "Vvedit 3-i sumvol: ", c3$
FOR i = 1 TO LEN(latter$)
    IF MID$(latter$, i, 1) = " " THEN
        IF check1 = true AND check2 = true AND check3 = true THEN k = k + 1
        check1 = false
        check2 = false
        check3 = false
    ELSEIF latter$(i) = c1$ THEN
        check1 = true
    ELSEIF latter$(i) = c2$ THEN
        check2 = true
    ELSEIF latter$(i) = c3$ THEN
        check3 = true
    END IF
NEXT
PRINT
PRINT "Kilkist sliv v re4enni sho mistjat zadani sumvolu: "; k
END